Along with the development of the society, users are expecting higher and higher rates of wireless access. As a Wireless Local Area Network (WLAN) is able to provide high-rates for wireless data access in a relatively small area, there has been wide application of the WLAN. Various techniques have been used in the WLAN, among which a technical standard with more application at present is IEEE 802.11b. This standard involves the frequency band of 2.4 GHz with a data transmission rate up to 11 Mbps. Other technical standards involving the same frequency band include IEEE 802.11g and the Bluetooth, where the data transmission rate of IEEE 802.11g is up to 54 Mbps. There are other new standards of the WLAN, such as IEEE 802.11a and ETSI BRAN Hiperlan2, which use the frequency band of 5 GHz with the transmission rate up to 54 Mbps as well.
Although there are various techniques for wireless access, most the WLAN utilize IP data packets for the data transmission. The specific WLAN access technique adopted by a wireless IP network is usually transparent to the upper-level of the IP network. Such a network is usually configured with Access Points (AP) for implementing wireless access of User Equipment (UE) and with IP transmission network which consists of network controlling and connecting devices for implementing the data transmission.
Along with the emergence and development of the WLAN, focus of research is shifting to the inter-working of the WLAN with various wireless mobile communications networks, such as Global System for Mobile communications (GSM), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Time Division-Synchronous Code Division Multiple Access (TD-SCDMA), and CDMA2000. In accordance with the 3rd Generation Partnership Project (3GPP) standards, the UE is able to connect via the access network of the WLAN with not only the Internet and Intranets but also the 3GPP home network and 3GPP visited network.
FIG. 1 is a schematic diagram illustrating the networking architecture of a WLAN inter-working with a 3GPP system under roaming circumstances. When a WLAN UE tries to get accessed under roaming circumstances, it will get connected with a 3GPP visited network via a WLAN access network. As some entities of the 3GPP visited network are inter-connected with corresponding entities of the 3GPP home network, for instance, a 3GPP Authentication, Authorization, Accounting (AAA) proxy in the visited network is connected with a 3GPP AAA server in the home network, a WLAN Access Gateway (WAG) in the visited network is connected with a Packet Data Gateway (PDG) in the home network, and etc., the WLAN UE is able to get accessed to the 3GPP home network. The shadow part of FIG. 1 shows the configuration for the service of 3GPP Packet Switch (PS) domain, i.e., the inter-working service of Scenario 3 in a 3GPP network.
FIG. 2 is a schematic diagram illustrating the networking architecture of a WLAN inter-working with a 3GPP system under non-roaming circumstances. When getting accessed locally, a WLAN UE will get connected directly to a 3GPP home network via a WLAN access network. The shadow part of FIG. 2 shows the configuration for the service of a 3GPP PS domain, i.e., service of Scenario 3 in a 3GPP home network.
As shown in FIG. 1 and FIG. 2, a 3GPP system primarily includes Home Subscriber Server (HSS)/ Home Location Register (HLR), 3GPP AAA server, 3GPP AAA proxy, WAG, PDG, Charging Gateway (CGw)/Charging information Collecting Function (CCF) and Online Charging System (OCS). A user equipment, a WLAN access network, and all the entities of the 3GPP system together constitute a 3GPP-WLAN inter-working network, which can be used as a WLAN service system. In this service system, the 3GPP AAA server is in charge of the authentication, authorization, and accounting of a user, collecting the charging information sent from the WLAN access network and transferring the information to the charging system; the PDG is in charge of the transmission of the user's data from the WLAN access network to the 3GPP network or other packet data networks; and the charging system receives and records the user's charging information transferred from the network while the OCS instructs the network to make periodical transmission of the online charging information in accordance with the expenses of the online charged users, makes statistics and conducts control.
The UE, on the other hand, primarily includes the TE, e.g., a lap-top computer; an Mobile terminal (MT), e.g., a cellular phone of a user; and a user identity card, e.g., a GSM Subscriber Identity Module (SIM), a 3G Universal Subscriber Identity Module (USIM), or an IP Multimedia Subsystem (IMS) SIM (ISIM), which is typically used by being inserted in a cellular phone.
In a hot area covered by the WLAN, after passing authentication and receiving authorization via the USIM/SIM in a cellular phone of the user, such a TE as the lap-top of a user may access an inter-working network of the WLAN and the 3GPP/3GPP2 system and use the Internet or the PS domain network of the 3GPP/3GPP2 system.
As the authentication and authorization processes using the USIM, SIM, or ISIM are much alike, the specific process of the TE accessing the network is hereinafter described by taking the USIM as an example. FIG. 3 is a schematic diagram illustrating a flowchart of a TE accessing the network using an USIM in the prior art.
Step 301: When having accessed the network and desiring to use a service in the network, the TE will receive an authentication request identity message sent from the network side. Since the identity of the TE itself is not a subscriber identity accepted in the 3GPP/3GPP2 network, the TE will link with a nearby cellular phone, i.e., an MT, via a local transmission protocol, such as the Bluetooth or an infrared interface so as to use the USIM in the MT as the identity of itself, i.e., the account, for accessing the network.
The above-said local transmission protocol refers to a short-distance transmission protocol, i.e., a transmission protocol only effective when the receiver and the transmitter are within a short distance, for example, the Bluetooth or the infrared interface. In other words, only when the distance between the TE and the MT is short will the local transmission protocol be effective, when the TE is relatively far from the MT, the local transmission protocol can not be used, i.e., the local transmission protocol is ineffective in that case, and it is the same below.
Step 302: After a link is set up between the TE and the MT via the local transmission protocol, the TE will forward the authentication request identity message from the network side to the MT.
Step 303: the MT acquires from the USIM the information of the user status identity accepted by the 3GPP/3GPP2 network, the identity includes International Mobile Subscriber Identity (IMSI) or International Mobile Person Identity (IMPI), or a temporary user's status identity named pseudonym assigned by the 3GPP/3GPP2 network.
Step 304: the MT sends to the TE a response message containing the identity by means of the local transmission protocol.
Step 305: the TE forwards to the network side the acquired response message containing the identity.
Step 306: the network side generates an authentication vector based on the received identity, and sends to the TE an authentication request containing the authentication vector.
Step 307: the TE forwards the authentication request containing the authentication vector to the MT.
Step 308: after receiving the authentication request containing the authentication vector, the MT asks the USIM to make calculation based on the authentication vector so as to detect the validity of the network; after the detection has passed, the MT acquires the information of authentication response value and key(s) from the calculation result of the USIM.
Step 309: the MT returns an authentication response message containing the authentication response value to the TE.
Step 310: the TE returns the authentication response message containing the authentication response value to the network side.
Step 311: the network side checks whether the authentication response value matches itself, if yes, sends a message of successful authentication to the TE and allows the TE to access the network, otherwise sends a message of failed authentication to the TE and rejects the request of the TE to access the network; meanwhile, the MT sends the information of key(s) to the TE such that the key(s) could be used by the TE when the TE accesses the network.
In the example mentioned above, the protocol of EAP(Extensible Authentication Protocol) is employed in the application layer between the network side, the TE and the MT while the interface protocol of 3GPP/3GPP2 between a terminal and a card is used between the MT and the USIM.
As can be seen from the above procedure, in the process of the TE making authentication and accessing the network via the MT using the USIM, as it is impossible to manage the TE that employs the MT, the resources of the MT are likely to be illegally utilized, which will lead to the loss of users' funds and inconvenience in the daily use of users.
In addition, in Step 311 above, the process of the network side sending the authentication result to the TE occurs at the same time of the MT sending the information of key(s) to the TE without a binding mechanism between the two processes, which causes a waste of the network resources.